The present invention relates to closure members for containers, bottles and the like, and, more particularly, to closure members having indicator means to indicate the number of times the container has been opened.
Present medical drugs have a predetermined therapeutic range in which the effects of taking the drug are beneficial. Under utilization of a drug may endanger the user with the drug's side effects without reaching levels necessary for a therapeutic action. On the other hand, over utilization may cause side effects or toxicity to a much greater extent than any possible benefit. Thus is critically important that a patient follow prescribed directions on medications, yet, frequently patients forget whether they have taken medication and either omit doses or repeat them.
This problem is particularly severe for elderly patients who are generally beset with multiple ailments requiring numerous drugs and directions. The fading memory and confusion that come with age further compound the problem. Oftentimes, elderly patients could well lead independent self-sufficient lives but for their inability to follow a therapeutic regimen necessary to their health and well-being. Caps of the "reminder" type will be an important adjunct in drug therapy as the number of elderly people increases and new potent drugs are utilized.
A considerable number of pill-timing schemes have been used to solve the problem of reminding a patient to take a dose of medicine or reminding him he has already taken that dose. The most used ones involve some scheme of compartmentalization of the necessary medication, such that the pills are placed in compartments labeled as to day, to dose number or time of day, or serially numbered. These devices are reasonably satisfactory if a responsible person is available and has the time and patience to fill the compartments properly.
In dispensing pills of a single type, a number of window-containing bottle caps have been invented. Through the window a movable element marked with an index is visible. In only a few devices does the indicating element index in position relative to the window each time the cap is loosened, removed, replaced, and re-tightened. Thus, by looking at the index mark displayed through the window, a user can see where in repetitive sequence of dose he or she is.
One of the most serious disadvantages of prior art devices of the window indexing type is that if the user does not turn the device far enough during the opening or closing process, the index will fail to advance properly, or fail to advance at all. These devices provide no indication that the index has failed to advance unless the user notices the index value before opening and then after closing, an unlikely event with most users, especially the elderly, who may not understand how the device operates. In addition, most prior art devices fail to provide positive locking in both directions of movement, thus, the index may be moved appropriately when the device is opened or closed, but additional movement is not prevented when the device is moved in the opposite direction thus allowing the index to drift, often causing failure, particularly after the device has been used over a period of time.
Specifically, the device of U.S. Pat. No. 4,011,829, issued Mar. 15, 1977 to Wachsmann et al., attempts to provide positive locking in both directions, but because of the direction of the tooth designed to prevent movement of the index upon closure, the device may not work reliably, particularly after wearing with use. Also, the device of Wachsmann does not provide space for the ratchet teeth to slide past the engagement teeth when the device is moving in a direction wherein such teeth should disengage, which may cause unreliable operation over a period of time. Another drawback of this device is its inclusion of the "child proofing" feature with the indexing feature, which makes the device more complex then necessary. Other features of this device, such as the method of providing the lost motion drive and the requirement of a post in the middle of the elements to hold the device together, also increase its complexity and cost of assembly.
The device of U.S. Pat. No. 3,151,599 issued Oct. 6, 1964 to Livingston provides positive locking in both directions, but it does so by means of very closely spaced projections that would be difficult to manufacture and assemble economically. Furthermore, this device does not provide space for the projections to move while sliding past each other when not engaged.
The device of U.S. Pat. No. 4,666,051 issued May 19, 1987 to Trick provides positive locking in both directions, but this device will work only with a bayonet type mount and requires that the bottom portion of the device be the container for the medication, therefore, the device is not suitable for separate attachment to an existing container cap. This device also does not provide an indication that is has worked properly.
Another disadvantage of these prior three art devices is that they cannot be distributed separately for attachment to a sealing cap of an existing bottle.
The device of European Patent 0 230 323, issued Jan. 24, 1986 to Schwab requires that the device be formed with a cavity in the top and bottom pieces. This device only provides a click when rotated in one direction, and does not provide positive locking of the indicator. Also, this device would appear to require close manufacturing tolerances and would be costly to assemble. Although the device would appear to be able to be attached to a separate sealing cap, the sealing cap would have to be of a particular dimension to mate with the cavity and cruciform projection, and therefore this device would be unable to be attached to a common, flat surfaced, sealing cap.
All the above prior art devices are designed to fit a specific cap or they are integrated into a particular bottle cap. None appear to be designed for installation on existing caps from various sources. In particular, none is designed to be installed on a cap having a flat upper surface, which is common for sealing caps in use today.
It is thus apparent that there is a need in the art for an improved indicator cap that provides positive controlled movement of the index on both opening and closing of the device, and that can be attached to an existing bottle cap, while also providing an indication to the user that the index has functioned properly each time the device is used.